feat(readmymind): alternates row, phone accessory key, phone-sized modal (phase 3 part 1)

The Read My Mind modal grows up and reaches phones:

- Alternate suggestions (the predictor's verify/redirect kinds) now render
  as tappable rows below the main field. Tapping one swaps it into the
  editable field; the edit you were making folds back into the row you
  leave, so toggling between alternates never loses typing. Rethink now
  records the WHOLE shown set (main + alternates) as rejected.
- Phones get a 🧠 key on the keyboard accessory bar (both simple and
  extended layouts), gated on the same synced readMyMindEnabled setting
  via an rmm-enabled marker class on the BAR element: setMode() rebuilds
  the buttons' innerHTML, so per-key state would be wiped. Synced at init
  and re-synced by applyHeaderVisibilitySettings() on every settings
  apply, so a live toggle needs no reload. The header button stays off
  phones.
- On phones the modal renders as a small dialog (mirrors modal-sm) instead
  of the full-screen default, with wrap-friendly finger-sized footer
  buttons. Not modal-sm itself: that caps desktop width at 340px and this
  modal wants 560px there.
- On touch devices the ready/swap paths no longer focus the field, so the
  OS keyboard does not pop over the alternates that just rendered.
- New static guard test/readmymind-phone-key.test.ts pins the dual-template
  key, the marker-class gating, the phone-hidden header button, the
  small-dialog phone modal, and the no-innerHTML discipline.

Part 2 of phase 3 (rethink steering, the free-text steer note) is next;
the API already accepts steer.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/readmymind-phone-key.test.ts

@@ -0,0 +1,76 @@
+// Port: none (pure static analysis — runs in CI, no browser/server).
+//
+// Read My Mind phase 3 part 1 guards: the modal's alternates row and the phone
+// keyboard-accessory 🧠 key. The mobile Playwright suite is excluded from CI,
+// so like test/mobile-header-buttons-policy.test.ts this parses the frontend
+// assets directly to pin the wiring that only a phone would exercise:
+//
+//  1. the 🧠 key ships in BOTH accessory-bar templates (setMode() swaps the
+//     bar's innerHTML between them, so a key present in only one layout would
+//     silently vanish when the user toggles `extendedKeyboardBar`) and routes
+//     to the shared modal;
+//  2. the key is hidden unless the bar carries the `rmm-enabled` marker class
+//     — gating must live on the BAR element because setMode() rebuilds the
+//     buttons — synced at init and re-synced by settings-ui.js on every
+//     settings apply (a live toggle needs no reload);
+//  3. the header 🧠 button STAYS off phones (the key is the phone surface);
+//  4. the modal renders on phones as a small dialog, not the full-screen
+//     default that phone `.modal-content` rules would impose;
+//  5. readmymind-ui.js keeps the no-innerHTML discipline (predictor output is
+//     injectable content) and renders alternates into the i18n-skipped
+//     container declared in index.html.
+import { describe, it, expect } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { fileURLToPath } from 'node:url';
+import { join } from 'node:path';
+
+const HERE = fileURLToPath(new URL('.', import.meta.url));
+const PUBLIC = join(HERE, '../src/web/public');
+const read = (name: string) => readFileSync(join(PUBLIC, name), 'utf-8');
+
+describe('read my mind phone key + alternates (static guards)', () => {
+  const accessory = read('keyboard-accessory.js');
+  const styles = read('styles.css');
+  const mobile = read('mobile.css');
+  const html = read('index.html');
+  const ui = read('readmymind-ui.js');
+  const settingsUi = read('settings-ui.js');
+  // Everything phone-specific lives in the max-width 430px block of mobile.css.
+  const phoneBlock = mobile.slice(mobile.indexOf('@media (max-width: 430px)'));
+
+  it('ships the 🧠 key in BOTH accessory bar templates and routes it to the modal', () => {
+    const simple = accessory.match(/_simpleButtons\s*:\s*`([\s\S]*?)`/)?.[1] ?? '';
+    const extended = accessory.match(/_extendedButtons\s*:\s*`([\s\S]*?)`/)?.[1] ?? '';
+    expect(simple).toMatch(/accessory-btn-rmm[^>]*data-action="readmymind"/);
+    expect(extended).toMatch(/accessory-btn-rmm[^>]*data-action="readmymind"/);
+    expect(accessory).toMatch(/case 'readmymind':/);
+    expect(accessory).toMatch(/openReadMyMind/);
+  });
+
+  it('hides the key until the bar carries rmm-enabled, synced at init and on settings apply', () => {
+    expect(styles).toMatch(/\.keyboard-accessory-bar \.accessory-btn-rmm \{\s*display: none;/);
+    expect(styles).toMatch(/\.keyboard-accessory-bar\.rmm-enabled \.accessory-btn-rmm \{\s*display: inline-flex;/);
+    // init() applies the gate as soon as the bar exists…
+    expect(accessory).toMatch(/this\.syncReadMyMind\(\);/);
+    // …and settings-ui re-syncs it on every settings apply (live toggle).
+    expect(settingsUi).toMatch(/KeyboardAccessoryBar\.syncReadMyMind/);
+  });
+
+  it('keeps the header 🧠 button off phones (the accessory key is the phone surface)', () => {
+    expect(phoneBlock).toMatch(/\.btn-icon-header\.btn-readmymind\s*\{\s*display: none !important;/);
+  });
+
+  it('renders the modal as a small dialog on phones, not the full-screen default', () => {
+    expect(phoneBlock).toMatch(/\.modal-content\.readmymind-modal\s*\{[^}]*height: auto;/);
+  });
+
+  it('declares the i18n-skipped alternates container and keeps the no-innerHTML discipline', () => {
+    expect(html).toMatch(/id="readMyMindAlternates"[^>]*data-i18n-skip/);
+    // Predictor output is injectable content: value/textContent only, ever.
+    // (`.innerHTML`: property ACCESS — the fileoverview's "never innerHTML"
+    // prose is allowed to say the word.)
+    expect(ui).not.toMatch(/\.innerHTML/);
+    expect(ui).toContain('readMyMindAlternates');
+    expect(ui).toMatch(/\.textContent = suggestion\.prompt/);
+  });
+});